Ovarian basaloid carcinoma with shadow cell differentiation.

Area of Science:

• Oncology
• Pathology
• Gynecologic Oncology

Background:

• Shadow cell differentiation (SCD) is characteristic of pilomatrixoma and follicular skin lesions.
• SCD has been infrequently observed in certain visceral carcinomas.
• Ovarian basaloid carcinoma is a rare entity, and SCD has not been previously described in this context.

Purpose of the Study:

• To report a unique case of ovarian basaloid carcinoma exhibiting shadow cell differentiation.
• To investigate the histological and immunohistochemical features of this rare tumor.
• To review the literature on SCD in visceral carcinomas.

Main Methods:

• Case presentation of a 45-year-old woman with a large ovarian mass.
• Surgical resection (adnexectomy and hysterectomy) followed by histopathological examination.
• Immunohistochemical analysis for squamous, glandular, and other markers (p63, CK5/6, CK7, CA125, ER, PR, vimentin, p53, beta-catenin).

Main Results:

• A high-stage, 14 cm ovarian basaloid carcinoma with extensive metastases was diagnosed.
• Histology revealed numerous shadow cells, characteristic of SCD, without glandular or teratoma components.
• Immunohistochemistry confirmed squamous differentiation markers (p63, CK5/6) and showed scattered positivity for CK7 and CA125. Beta-catenin positivity suggested Wnt pathway involvement.

Conclusions:

• This is the first reported case of shadow cell differentiation in ovarian basaloid carcinoma.
• The findings suggest that SCD can occur in ovarian basaloid carcinomas, expanding its known spectrum in visceral malignancies.
• Further research is warranted to understand the pathogenesis and clinical implications of SCD in ovarian cancers.